Hazelnuts: Nutrition Facts and Health Benefits

Hazelnuts are more than just a tasty snack—they pack a powerful nutritional punch and offer a wealth of health benefits. Whether enjoyed raw, roasted, or as an ingredient in your favorite dishes, hazelnuts bring unique flavors and vital nutrients to the table. In this article, we’ll take a close look at their nutritional composition and explore the science-backed benefits of making hazelnuts a regular part of your diet.

Hazelnuts Nutrition Facts

Hazelnuts are a small nut with a big nutritional profile. They are valued for their healthy fats, rich micronutrient content, and notable levels of antioxidants and bioactive compounds, making them a worthy addition to any diet. Let's break down the key nutrients that hazelnuts offer.

Table 1: Major Nutritional Components of Hazelnuts

Macronutrient Profile

Hazelnuts are calorie-dense, providing about 650 kcal per 100 grams, largely from fat. Fat makes up the bulk of hazelnut weight (56–61%), and most of this fat is the heart-healthy monounsaturated type—primarily oleic acid (around 80–83% of total fatty acids) 1 2 5. They also contain some polyunsaturated fats, like linoleic acid, and small amounts of saturated fats (palmitic and stearic acids) 2 5.

Proteins account for 13–15% of the nut, with an impressive amino acid profile. Glutamic acid, arginine, and aspartic acid are the most abundant, contributing to both nutrition and the characteristic taste of hazelnuts. However, lysine and tryptophan are limiting amino acids 1.

Carbohydrates are relatively low, typically 6–17 grams per 100 grams, with a significant portion as dietary fiber—making hazelnuts a fiber-rich food 1. Sugars are present in small amounts, mainly as sucrose 1 5.

Micronutrients and Phytochemicals

Hazelnuts are a true micronutrient powerhouse:

• Vitamin E: Hazelnuts shine as one of the richest sources of vitamin E among all nuts, offering 24 mg per 100 grams, predominantly as α-tocopherol 1 5 10. This potent antioxidant is crucial for cell protection and skin health.
• B Vitamins: They supply modest amounts of B vitamins (B1, B2, B6, folate), supporting energy metabolism and brain health 1.
• Minerals: Hazelnuts are loaded with potassium, magnesium, calcium, phosphorus, and trace elements like iron, copper, selenium, and zinc 1 3 5. Just 50 grams can supply significant portions of your daily requirements for several of these minerals 3.
• Phenolic Compounds: Especially in the skins, hazelnuts are rich in antioxidant polyphenols—flavan-3-ols (catechin, epicatechin), flavonols (quercetin derivatives), and hydrobenzoic acids (gallic acid) 7 9. These compounds support the body's defenses against oxidative stress.

Special Notes: The Impact of Processing

The form in which hazelnuts are consumed matters. Skins contain the highest concentration of phenolics and antioxidants, so eating whole, unpeeled nuts is best for maximizing health benefits. Roasting does not significantly reduce the total antioxidant content, but removing the skin does 7.

Hazelnuts Health Benefits

Beyond their stellar nutritional content, hazelnuts have been linked to a variety of health benefits, from supporting heart health to offering neuroprotection and more. Here’s a summary of what scientific research says about the positive impacts of hazelnuts.

Table 2: Evidence-Based Health Benefits of Hazelnuts

Cardiovascular Support

Hazelnuts are most celebrated for their role in promoting heart health. Multiple clinical studies and meta-analyses show that diets rich in hazelnuts significantly reduce LDL ("bad") cholesterol and total cholesterol levels, while either maintaining or slightly increasing HDL ("good") cholesterol 4 6 10. These effects are attributed to their high monounsaturated fat content, vitamin E, and antioxidant compounds.

• Lipid Profile: Regular intake of 30–69g/day improves cholesterol ratios without affecting triglycerides or body weight 4 6 10.
• Endothelial Function: Hazelnuts enhance flow-mediated dilation (a marker of blood vessel health), reduce LDL oxidation, and lower vascular inflammation markers (hs-CRP, sVCAM-1) 6.
• Consistent Results: These benefits are observed regardless of whether hazelnuts are consumed whole, sliced, or ground 10.

Antioxidant and Anti-inflammatory Effects

Hazelnuts are rich in antioxidants, especially vitamin E and polyphenols in the skin. These compounds help neutralize free radicals, reducing oxidative stress—a key factor in aging and chronic disease development 5 7 9.

• Maximizing Benefits: Consuming nuts with their skins delivers the highest antioxidant protection 7.
• Anti-inflammatory Action: Intervention studies show reductions in inflammatory biomarkers after hazelnut-enriched diets 6.

Blood Sugar and Metabolic Health

Laboratory research shows that hazelnuts, like other nuts, inhibit enzymes (intestinal α-glucosidase) involved in carbohydrate digestion, potentially reducing post-meal blood sugar spikes 5. Their low sugar content and high fiber also support stable blood sugar levels.

Weight Management

Despite their high energy content, studies consistently find that hazelnut consumption does not lead to weight gain. This is likely due to their effects on satiety, energy absorption, and metabolism 4 10. In trials, participants consuming hazelnuts daily maintained stable body weight and BMI.

Neuroprotection and Cognitive Benefits

Hazelnuts have long been valued in traditional medicine for supporting brain health. Modern pharmacological reviews suggest that hazelnut’s nutrients and phytochemicals (vitamin E, B vitamins, polyphenols, healthy fats) support memory, protect against neurodegeneration, and may help reduce risk factors for diseases like Alzheimer's 8.

Antimicrobial Properties

Hazelnut extracts have shown the ability to inhibit the growth of certain bacteria and fungi in laboratory settings, suggesting potential for supporting immune defense 2.

Additional Considerations

The Importance of Form and Processing

• Whole vs. Processed: Eating hazelnuts with skins maximizes antioxidant intake 7.
• Roasting: Does not substantially reduce the antioxidant capacity, but can alter the profile of some phenolic compounds 7.
• Portion Size: A daily serving of 30–50g is effective and safe for most adults, providing significant nutritional and health benefits without excess calories 3 4 10.

Allergen Alert

As with all tree nuts, hazelnuts can cause allergic reactions in sensitive individuals. Always introduce them cautiously if you have nut allergies.

Conclusion

Hazelnuts are much more than a delicious snack—they’re a true superfood packed with nutrients and powerful health-promoting properties. Here’s what we covered:

• Nutrient-Dense: High in healthy fats, vitamin E, fiber, and key minerals (potassium, magnesium, selenium, iron, copper, zinc).
• Antioxidant Powerhouse: Especially when consumed with their skins, hazelnuts deliver robust antioxidant and anti-inflammatory effects.
• Heart Health: Regular consumption lowers LDL cholesterol and inflammatory markers, improving overall cardiovascular risk factors.
• Blood Sugar and Weight: Support healthy blood sugar regulation and do not cause weight gain despite caloric density.
• Brain and Immune Support: Potential neuroprotective benefits and antimicrobial properties.
• Best Practices: For the greatest health impact, enjoy hazelnuts whole and unpeeled, and aim for a serving size of 30–50g per day.

Hazelnuts are a versatile, science-backed addition to a healthy eating pattern. Including them regularly can help you enjoy their full spectrum of nutritional and health benefits.